title: Prophylactic role of oral L-arginine on histological and contractile changes in a rat chronic bladder injury model.
abstract: BACKGROUND
  The effect of L-arginine on bladder tissue structure and function in a rat bladder injury model were investigated.
  
  
  METHODS
  24 male Sprague-Dawley rats were used. The control group received a regular diet. The L-arginine group received oral L-arginine (1 g/day). The protamine sulfate (PS) group received intravesical PS every 48 h (0.5 ml, 5 mg/ml). L-arginine was administered to the PS+L-arginine group in addition to PS. At the end of 1 week, bladder tissues were processed for histological and functional studies.
  
  
  RESULTS
  The PS group revealed urothelial damage with glycosaminoglycan layer irregularity and mast cell infiltration which was not evident in the PS+L-arginine group. 120 mM potassium and electrical field stimulation (EFS)-induced contractions in the PS group were significantly lower than in other groups, whereas carbachol-induced contractions were not significantly different. Relaxation responses of precontracted strips to EFS and isoproterenol did not reveal a significant decrease in the PS group, whereas L-arginine significantly enhanced these responses in PS-treated animals.
  
  
  CONCLUSIONS
  Intravesical PS causes urothelial damage and inflammation that is associated with significant changes in rat bladder tissue contractility. Oral L-arginine treatment is found to prevent these histological and contractile alterations. Our findings may indicate the nitric oxide-cGMP pathway as a possible therapeutic target in various bladder diseases associated with urothelial damage.
authors.affiliation: Department of Urology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Abdurrahman
authors.initials: A
authors.lastname: Ozgür
authors.forename: Fikret Fatih
authors.initials: FF
authors.lastname: Onol
authors.forename: Feriha
authors.initials: F
authors.lastname: Ercan
authors.forename: Tufan
authors.initials: T
authors.lastname: Tarcan
mesh_terms: D000284:Administration, Oral; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000008:administration & dosage*; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects*; D011188:Potassium / Q000378:metabolism; D011479:Protamines; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D001745:Urinary Bladder Diseases / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D019459:Urothelium / Q000187:drug effects / Q000473:pathology
chemical_list: D000318:Adrenergic beta-Agonists; D018679:Cholinergic Agonists; D011479:Protamines; D002217:Carbachol; D001120:Arginine; D007545:Isoproterenol; D011188:Potassium